2,130 research outputs found
The high-gain teacher
The improvement of teacher performance requires the accurate identification of a teacher\u27s strengths and weaknesses. However, effective teachers, in addition to utilizing certain effective teaching skills, are strengthened by certain affective skills which are difficult to identify and, consequently, to measure. The research has identified a whole host of teacher behaviors that are clearly related to student achievement. This study, in addition to assessing those observable teacher behaviors, sought to particularize their personality characteristics and measured their feelings of self-efficacy, which refers to the extent which teachers believe that they have the capacity to affect student performance;Seventy classes, thus teachers, were involved. A change score report for the entire year in both criterion-referenced and norm-referenced tests (pretests in September and posttests in May) was created subsequent to each spring testing. Those teachers whose average change score was greater than that of his/her school organization\u27s average change score were classified as high-gain teachers. In addition, the teachers in the project were evaluated utilizing a research-based performance evaluation instrument. Thus, both reports of individual teacher evaluations and the achievement measures of their students were available;Teachers and their supervisors were asked to complete the SIM Teacher Performance Evaluation Instrument and a comparison of ratings was conducted. To determine the personal characteristics of the high-gain teachers, the Personal Profile System was used. Finally, to assess the feelings of self-efficacy, the Responsibility for Student Achievement Questionnaire was utilized;Findings. (1) High-gain teachers rated themselves significantly higher than their supervisors rated them on 18 out of 25 effective teaching criteria. (2) High-gain teachers exhibited characteristics in all four of the dimensions of behavior assessed by the Personal Profile System: 42% exhibited an influencing of others style of behavior, 29% compliance, 19% steadiness, and 10% dominance. (3) High-gain teachers have a strong belief that they have control of factors that influence students\u27 successes and failures in the classroom. (4) There was no significant difference between male and female high-gain teachers in feelings of self-efficacy
Juvenile Hormone Biosynthesis in Insects: What Is New, What Do We Know, and What Questions Remain?
Our understanding of JH biosynthesis has significantly changed in the last years. In this review I would like to discuss the following topics: (1) the progresses in understanding the JH biosynthesis pathway. Access to genome sequences has facilitated the identification of all the genes encoding biosynthetic enzymes and the completion of comprehensive transcriptional studies, as well as the expression and characterization of recombinant enzymes. Now the existence of different flux directionalites, feed-back loops and pathway branching points in the JH biosynthesis pathways can be explored; (2) the new concepts in the modulation of JH synthesis by allatoregulators. The list of putative JH modulators is increasing. I will discuss their possible role during the different physiological states of the CA; (3) the new theoretical and physiological frameworks for JH synthesis analysis. I will discuss the bases of the flux model for JH biosynthesis. JH plays multiple roles in the control of ovary development in female mosquitoes; therefore, the CA presents different physiological states, where JH synthesis is altered by gating the flux at distinctive points in the pathway; (4) in the final section I will identify new challenges and future directions on JH synthesis research
The MIPSGAL View of Supernova Remnants in the Galactic Plane
We report the detection of Galactic supernova remnants (SNRs) in the mid-infrared (at 24 and 70 μm), in the coordinate ranges 10° < l < 65° and 285° < l < 350°, |b| < 1°, using MIPS aboard the Spitzer Space Telescope. We search for infrared counterparts to SNRs in Green's catalog and identify 39 out of 121, i.e., a detection rate of about 32%. Such a relatively low detection fraction is mainly due to confusion with nearby foreground/background sources and diffuse emission. The SNRs in our sample show a linear trend in [F_8/F_(24)] versus [F_(70)/F_(24)]. We compare their infrared fluxes with their corresponding radio flux at 1.4 GHz and find that most remnants have a ratio of 70 μm to 1.4 GHz which is similar to those found in previous studies of SNRs (with the exception of a few that have ratios closer to those of H II regions). Furthermore, we retrieve a slope close to unity when correlating infrared (24 and 70 μm) with 1.4 GHz emission. Our survey is more successful in detecting remnants with bright X-ray emission, which we find is well correlated with the 24 μm morphology. Moreover, by comparing the power emitted in the X-ray, infrared, and radio, we conclude that the energy released in the infrared is comparable to the cooling in the X-ray range
Crecimiento postraumático en padres de niños y adolescentes con cáncer.
El cáncer puede provocar reacciones psicológicas
negativas. No obstante, la lucha al abordar los problemas
oncológicos también puede dar lugar a cambios
psicológicos positivos que demuestran la fortaleza del
ser humano, siendo una de ellas el crecimiento postraumático
(CPT). El objetivo de esta revisión narrativa fue
revisar y analizar los artículos, publicados durante los
años 2000 a 2018 y disponibles en distintas bases de
datos, sobre el CPT en padres y madres de niños y adolescentes
con cáncer en el ámbito pediátrico.
Se identificaron 20 estudios que incluían 2.422 sujetos,
mayoritariamente madres (n=1.788), y que analizaban
el CPT en función del parentesco, evolución y tipo
de enfermedad del hijo, así como factores predictores
del mismo. Tanto padres como madres, son capaces de
desarrollar CPT como consecuencia de la experiencia
del cáncer de sus hijos, siendo ellas quienes experimentan
mayores niveles. En comparación con otras muestras
como progenitores de niños con diabetes tipo I o
de niños sanos, o pacientes adultos con osteosarcoma,
los padres y madres de niños con cáncer refieren mayor
CPT. Asimismo, se observan factores que influyen en el
desarrollo del CPT, como el contexto cultural, el procesamiento
cognitivo, el ajuste a la enfermedad y ciertos
rasgos de personalidad.
La evidencia científica publicada avala la existencia
de CPT en madres y padres de hijos con cáncer. No
obstante, sería necesario realizar estudios objetivos,
longitudinales, con muestras homogéneas de mayor
tamaño, para diseñar intervenciones dirigidas a promocionar
ese CPT y no centrarse solo en los aspectos
negativos de la enfermedad.post-print213 K
Negative Feedbacks by Isoprenoids on a Mevalonate Kinase Expressed in the Corpora Allata of Mosquitoes
Background Juvenile hormones (JH) regulate development and reproductive maturation in insects. JHs are synthesized through the mevalonate pathway (MVAP), an ancient metabolic pathway present in the three domains of life. Mevalonate kinase (MVK) is a key enzyme in the MVAP. MVK catalyzes the synthesis of phosphomevalonate (PM) by transferring the gamma-phosphoryl group from ATP to the C-5 hydroxyl oxygen of mevalonic acid (MA). Despite the importance of MVKs, these enzymes have been poorly characterized in insects. Results We functionally characterized an Aedes aegypti MVK (AaMVK) expressed in the corpora allata (CA) of the mosquito. AaMVK displayed its activity in the presence of metal cofactors. Different nucleotides were used by AaMVK as phosphoryl donors. In the presence of Mg2+, the enzyme has higher affinity for MA than ATP. The activity of AaMVK was regulated by feedback inhibition from long-chain isoprenoids, such as geranyl diphosphate (GPP) and farnesyl diphosphate (FPP). Conclusions AaMVK exhibited efficient inhibition by GPP and FPP (Ki less than 1 mu M), and none by isopentenyl pyrophosphate (IPP) and dimethyl allyl pyrophosphate (DPPM). These results suggest that GPP and FPP might act as physiological inhibitors in the synthesis of isoprenoids in the CA of mosquitoes. Changing MVK activity can alter the flux of precursors and therefore regulate juvenile hormone biosynthesis
Smallholder access to quality and diverse seed in Uganda: implications for food security
This policy briefs presents smallholder farmers' preferences and major challenges when accessing seed in Uganda. It reflects on the weaknesses of the formal and informal seed production and distribution systems and presents some practical recommendations for putting in place alternative and integrative seed quality control systems that can help fill in the gaps that the formal and informal systems cannot address separately
Expanded Very Large Array Observations of the Nebula Around G79.29+0.46
We have observed the radio nebula surrounding the Galactic luminous blue variable candidate G79.29+0.46 with the Expanded Very Large Array (EVLA) at 6 cm. These new radio observations allow a morphological comparison between the radio emission, which traces the ionized gas component, and the mid-IR emission, a tracer of the dust component. The InfraRed Array Camera (8 μm) and the Multiband Imaging Photometer for Spitzer (24 μm and 70 μm) images have been reprocessed and compared with the EVLA map. We confirm the presence of a second shell at 24 μm and also provide evidence for its detection at 70 μm. The differences between the spatial morphology of the radio and mid-IR maps indicate the existence of two dust populations, the cooler one emitting mostly at longer wavelengths. Analysis of the two dusty, nested shells have provided us with an estimate of the characteristic timescales for shell ejection, providing important constraints for stellar evolutionary models. Finer details of the ionized gas distribution can be appreciated thanks to the improved quality of the new 6 cm image, most notably the highly structured texture of the nebula. Evidence of interaction between the nebula and the surrounding interstellar medium can be seen in the radio map, including brighter features that delineate regions where the shell structure is locally modified. In particular, the brighter filaments in the southwest region appear to frame the shocked southwestern clump reported from CO observations
Microarray analysis of relative gene expression stability for selection of internal reference genes in the rhesus macaque brain
Abstract Background Normalization of gene expression data refers to the comparison of expression values using reference standards that are consistent across all conditions of an experiment. In PCR studies, genes designated as "housekeeping genes" have been used as internal reference genes under the assumption that their expression is stable and independent of experimental conditions. However, verification of this assumption is rarely performed. Here we assess the use of gene microarray analysis to facilitate selection of internal reference sequences with higher expression stability across experimental conditions than can be expected using traditional selection methods. We recently demonstrated that relative gene expression from qRT-PCR data normalized using GAPDH, ALG9 and RPL13A expression values mirrored relative expression using quantile normalization in Robust Multichip Analysis (RMA) on the Affymetrix® GeneChip® rhesus Macaque Genome Array. Having shown that qRT-PCR and Affymetrix® GeneChip® data from the same hormone replacement therapy (HRT) study yielded concordant results, we used quantile-normalized gene microarray data to identify the most stably expressed among probe sets for prospective internal reference genes across three brain regions from the HRT study and an additional study of normally menstruating rhesus macaques (cycle study). Gene selection was limited to 575 previously published human "housekeeping" genes. Twelve animals were used per study, and three brain regions were analyzed from each animal. Gene expression stabilities were determined using geNorm, NormFinder and BestKeeper software packages. Results Sequences co-annotated for ribosomal protein S27a (RPS27A), and ubiquitin were among the most stably expressed under all conditions and selection criteria used for both studies. Higher annotation quality on the human GeneChip® facilitated more targeted analysis than could be accomplished using the rhesus GeneChip®. In the cycle study, multiple probe sets annotated for actin, gamma 1 (ACTG1) showed high signal intensity and were among the most stably expressed. Conclusions Using gene microarray analysis, we identified genes showing high expression stability under various sex-steroid environments in different regions of the rhesus macaque brain. Use of quantile-normalized microarray gene expression values represents an improvement over traditional methods of selecting internal reference genes for PCR analysis
New ATCA, ALMA and VISIR observations of the candidate LBV SK-67266 (S61): the nebular mass from modelling 3D density distributions
We present new observations of the nebula around the Magellanic candidate
Luminous Blue Variable S61. These comprise high-resolution data acquired with
the Australia Telescope Compact Array (ATCA), the Atacama Large
Millimetre/Submillimetre Array (ALMA), and VISIR at the Very Large Telescope
(VLT). The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA
map, with 0.8 arcsec resolution, allowed a morphological comparison with the
H Hubble Space Telescope image. The radio nebula resembles a spherical
shell, as in the optical. The spectral index map indicates that the radio
emission is due to free-free transitions in the ionised, optically thin gas,
but there are hints of inhomogeneities. We present our new public code RHOCUBE
to model 3D density distributions, and determine via Bayesian inference the
nebula's geometric parameters. We applied the code to model the electron
density distribution in the S61 nebula. We found that different distributions
fit the data, but all of them converge to the same ionised mass, ~0.1 , which is an order of magnitude smaller than previous estimates. We
show how the nebula models can be used to derive the mass-loss history with
high-temporal resolution. The nebula was probably formed through stellar winds,
rather than eruptions. From the ALMA and VISIR non-detections, plus the derived
extinction map, we deduce that the infrared emission observed by space
telescopes must arise from extended, diffuse dust within the ionised region.Comment: 17 pages, 9 figures. Authors list corrected. In press in MNRAS.
RHOCUBE code available online ( https://github.com/rnikutta/rhocube
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